Exponential smoothing of seasonal data: a comparison

A parsimonious method of exponential smoothing is introduced for time series generated from a combination of local trends and local seasonal effects. It is compared with the additive version of the Holt–Winters method of forecasting on a standard collection of real time series. Copyright © 2001 John Wiley & Sons, Ltd.     

Phosphorylation of DARPP-32 by Cdk5 modulates dopamine signalling in neurons

The physiological state of the cell is controlled by signal transduction mechanisms which regulate the balance between protein kinase and protein phosphatase activities. Here we report that a single protein can, depending on which particular amino-acid residue is phosphorylated, function either as a kinase or phosphatase inhibitor. DARPP-32 (dopamine and cyclic AMP-regulated phospho-protein, relative molecular mass 32,000) is converted into an inhibitor of protein phosphatase 1 when it is phosphorylated by protein kinase A (PKA) at threonine 34. We find that DARPP-32 is converted into an inhibitor of PKA when phosphorylated at threonine 75 by cyclin-dependent kinase 5 (Cdk5). Cdk5 phosphorylates DARPP-32 in vitro and in intact brain cells. Phospho-Thr 75 DARPP-32 inhibits PKA in vitro by a competitive mechanism. Decreasing phospho-Thr 75 DARPP-32 in striatal slices, either by a Cdk5-specific inhibitor or by using genetically altered mice, results in increased dopamine-induced phosphorylation of PKA substrates and augmented peak voltage-gated calcium currents. Thus DARPP-32 is a bifunctional signal transduction molecule which, by distinct mechanisms, controls a serine/threonine kinase and a serine/threonine phosphatase.     

Towards a transgenic model of Huntington's disease in a non-human primate

Non-human primates are valuable for modelling human disorders and for developing therapeutic strategies; however, little work has been reported in establishing transgenic non-human primate models of human diseases. Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor impairment, cognitive deterioration and psychiatric disturbances followed by death within 10-15 years of the onset of the symptoms. HD is caused by the expansion of cytosine-adenine-guanine (CAG, translated into glutamine) trinucleotide repeats in the first exon of the human huntingtin (HTT) gene. Mutant HTT with expanded polyglutamine (polyQ) is widely expressed in the brain and peripheral tissues, but causes selective neurodegeneration that is most prominent in the striatum and cortex of the brain. Although rodent models of HD have been developed, these models do not satisfactorily parallel the brain changes and behavioural features observed in HD patients. Because of the close physiological, neurological and genetic similarities between humans and higher primates, monkeys can serve as very useful models for understanding human physiology and diseases. Here we report our progress in developing a transgenic model of HD in a rhesus macaque that expresses polyglutamine-expanded HTT. Hallmark features of HD, including nuclear inclusions and neuropil aggregates, were observed in the brains of the HD transgenic monkeys. Additionally, the transgenic monkeys showed important clinical features of HD, including dystonia and chorea. A transgenic HD monkey model may open the way to understanding the underlying biology of HD better, and to the development of potential therapies. Moreover, our data suggest that it will be feasible to generate valuable non-human primate models of HD and possibly other human genetic diseases.     

Experimental manipulations of precipitation seasonality: effects on oak ( Quercus ) seedling demography and physiology

Predicted changes in regional precipitation patterns and soil moisture caused by anthropogenic trace gas emissions may affect the distribution and abundance of woody plants in arid and semiarid regions. To test the response of woody plants to potential changes in precipitation regimes, we manipulated summer and winter precipitation on plots that contained seedlings of Quercus emoryi Torr. (Emory oak), the dominant tree in oak savannas of the southwestern United States. Throughout the growing season, we monitored seedling survival and physiology (predawn leaf water potential, midday instantaneous gas exchange, and leaf carbon isotope discrimination). Seedling survival and physiological performance differed little between treatments, which embodied 50% changes to quantities of summer and winter precipitation, and encompassed a continuum of precipitation from 359 mm · year -1 to 846 mm · year -1 . However, survival and physiological performance of seedlings were negatively impacted by seasonal environmental conditions common to all treatments, especially during the annual pre-'monsoon' drought. Seedling predawn leaf water potentials, net CO 2 assimilation, and stomatal conductance indicate that growing conditions for Q. emoryi seedlings at this site are generally restricted to periods with adequate soil moisture (i.e., April and August). Results contrast with an assumption implicit to the ""two-layer"" soil water resource partitioning hypothesis that woody plants in all life history stages are more dependent upon winter than summer precipitation. In fact, summer precipitation appears more important than winter precipitation for Q. emoryi seedling recruitment and growth.     

Introduction

The question of the existence of intelligent life on other worlds has never been a purely scientific one. Philosophical, religious and literary issues have been intertwined with scientific ones throughout the history of the “plurality of worlds” debate. This collection of papers in –Studies in History and Philosophy of Science– explores the interrelation of science, philosophy, religion and literature in debates about extraterrestrial life.     

Inhibition ofNeisseria catarrhalis NE-11 transformation

Zusammenfassung Nachweis, dass die Transformation vonNeisseria catarrhalis sich mit Antibiotika und Chemikalien hemmen lässt, die ihrerseits die Eiweiss-und Zellwandsynthese hemmen. Daraus wird geschlossen, dass Eiweiss- und Zellwandsynthese zur Transformation nötig sind.

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Eastern Kentucky University Grant No. 05-03-422-41 was the sole support of this project and was given to the last author.     

Catecholamines in adult iron deficiency patients.

Patients with iron deficiency whether uncomplicated or associated with other types of anemias, had plasma catecholamine levels which were significantly increased above normal controls. Patients with a variety of other anemias had no significant increase in catecholamine levels. Plasma catecholamine levels in uncomplicated iron deficient patients approached normal values as early as 3 h following oral FeSO4.